Production of ammonia and catalytic agents for use therein.



4 UNITED,STATESTATENT. OFFICE.

RHINE, AND GEORG- STERN OFMANN HEIM, GERMANT Y, lASSIGNORS TO-BADISGHE ANILIN & SODA IEAIBRIK, F LUDWIGtSHAEENj-ON-TIIEBHINE, GERMANY, ACOBPO- 'mrrron.

- rnonoorron or AMMONIA Ann on'rrli'rv'rrc AGENTS non usnmnnnnm.

' Specifieationof iettersPatent I I Patented July 29 191 3.

' No Drawing. Original application filed December 24, 1910, Serial No. 599 100. f Divided and this application filed January 1Q,1912; Serial No. 670,446. v 1 q To all whom it may 'co'ncem';

. Be it known that we, CARnBosoH, ALWIN MrrrAscH, HANS WOLF,; and Gross STERN,

subjects the first and. fourth :of the King of Prussia, the second of the ,King of Saxony, and the third of the King'of Bavaria,

residing the first three at Ludwigshafenbm the-Rhine and the fourth atManheim, all in Germany, have invented certain new and useful improvements in the Productionjof Ammonia and Catalytic Agents for Use Therein, which invention is divided out of our ape plication for Letters Patent filed December 24', 1910, Serial No. 599,100, and of which the following is a specification.

Our invention relates tojthe manufacture of ammonia by synthesis from its elements and in catalytic-agents for use inthe said manufacture.

patent Serial No.599,101-we have described- ,a new form of iron which is capable ofuse as a catalytic agent in the manufacture of ammonia from its elements, and we have further shown that the catalytic power of iron can be improved by the presence of certain bodies which we have termed promoters.

We have furthershown in the said spcifi-- cation that certain other bodies act as contact poisons and tend toldestroy the catalytic power of iron for converting a mixture of nitrogen and hydrogen 1nto ammonia.

Further, in the application for-Patent Serial No.- 599,190 is described and claimed generically the production of ammonia when making use of a catalytic agent, together with a promoter ineach case. In this application we now desire to claim specifically the production of ammonia while making use of osmium and a promoter, and also such catalytic mixture itself. Such production and catalytic mixture are claimed generically in theaforesaid application Serial No.

. 599,100, but are not claimed specifically therein. Inflcontinuing .our researches-onthe synthetic manufacture of ammonia from its elements, we have further-discovered that the power ofosmium as a catalyticagent for the production of ammon-iaby synthesis can also be improved by the presence of promoters, and that otherbodies act as contact poi sons. As a general rule admitting of sev In the speclfi cation ot our application for.

eral exceptions, compounds of the' 'alkalibe present as such or in the form of a suitable compound thereof Since it is evident that durlng the passage of the miirture of hydrogen and nitrogen over the contact ma-.

terial the body or promoter added may vundergo some chemical change, we do not wish to be understood as confining our invention compounds'of the to the use of the specific elements mentioned.

Although we have mentioned a number of bodies which actas promoters and a number of instances of contact poisons, thesein stances do not exhaust the number of bodies having the effects mentioned. We. have found that an enormous number of bodies have moreor less action'in the ways mentioned, and these bodies belong to; various classes of chemical substances, so that it'is impossible to give a-definition of promoters in terms, making the class of promoters coincident with some class or classesof chemical bodies. Thus, we have. ifound v that bodies that are not alkaline earths or alka; line metals or compounds. thereof. will act ,as promoters, and we do not desire our patent to be restricted to promoters which fall into the classes of alkaline earths and, a'lkalis. We have devised a simple test whereby'lit can readily be ascertained Whether any body is a promoter in thesense of this specifica- 'tion. The test is conducted as follows.

Prepare an intimate mixture of the'test body This may be done in some cases by mechanical mixture, in others by chemical precipitation on the catalyst, or by mixing amalgams of the two metals'and then distilling off the mercury, or by reducing, a mixture of their chloride or 'of their oxids with hydrogen vor ammonia, or by mixing solutions of osmium compound and test body and evaporating to dryness, or'by'tasuitable combination of one ormo're these methods. Set the product .35 i ten per cent-of its weight of potassium so obtained as a catalyst in a tube-furnace side by side with another tube containing an equal quantity of the untreated catalyst Without any addition, and pass equal currents of a mixture of nitrogen and hydrogen in their combining proportions through both tubes under identical conditions, and measure the quantity of ammonia obtained in 3 both cases. If the yield ofammonia be increased by the treatment with the added body, this may be regarded as'a promoter.

' As instances of the bodies which can be employed as promoters according to our invention, we mention oxids or other suitable compounds of the group of alkali metals, or

w the alkaline earth metals, of the group of thee'arth metals, of the group of the-rare earth metals, also silica, tantalum, niobium, and the like. We include in this invention both alkali metals and alkali earth metals under the phrase alkali-forming metals. As

a. general rule, those metals or compounds of those metals which yield oxids and salts which are non-reducible by hydrogen are suitable for use as promoters. Generally speaking, any one or more of the aforesaid promotersca'n be employed.

, When working according to this invent on, yields of 8% or more of ammonia can easily be obtained.

- The-following example will serve. to illustr'ate further the nature of our-invention,

which, however, is not inany way confined to this example. Mix osmium, or osmium oxid hydrate (cfBerichte, 40, 1387), with l osmate, and then place the mixture in the contact tube and pass. a current of pure hydrogen through the tube while heating.- A a catalytic agent is obtained which gives better results than does the untreated osmium. Ammonia can for instance be obtained by passing a mixture of pure nitrogen and hydrogen in combining proportions over the catalytic agent at about 450 (land at a pressure of 150 atmospheres.

'It has been found advantageous that the catalytic mixture consist of osmium and a sub-group of the periodic system. Thus, for

promoter which belongs preferablyto adifferent group or, at any rate, to a different 4. An activecatalyst. for the of ammonia from itsf elements containing "scribingwitnesses.

instance, mixtures of osmium and lithium, orof osmium-and sodium, or of osmium and thorium, are also suitable for the purposes of this invention.

We do not claim in this present application generically the production of ammonia while making use of a catalytic agent together with a promoterpin'ea'ch case,zsucl1 production'an'd such catalytic mixturesbe--' ing embodied in the claims "of the aforesaid "applicationfor patent Serial No. 599,100, filed December '24:, 1910.

Now .what we claim is 1. An active catalyst'forthemanufacture of ammonia from its elementscontaining osmium and" a promoter.

2. An active catalyst forthe manufacture-- osmium; and an oxid metal.

An active catalyst for the manufacture I osmium and potassium oxidfl p manufacture of ammonia *fromits elements containing osmium and; hydrated potassium oxid.

by. passing"a mixture containing nitrogen and hydrogen free from-contact poison over an active catalyst containing osm um and apromoter. 1 6'. The process (if-manufacturing ammonia of ammonia) from its elements containing of an alkali-forming 5. The process of manufacturing ammonia by pass'ingfa mixture containing nitrogen and hydrogen free from contact poison over an actlve catalyst containing o'smium-andan 'oxid o'f-an alkali-forming metal.

bypassing a mixture containing nitrogen and hydrogen free from contact poison'over an active catalyst containing osmium and potassium oxid.

J Anne. LLoYD,

A.O. TI'r'rMAI IN.

ALWIN MITTASCH.

. i v l f.- -7. Therprocess of manufacturingammon1a1 In-testimony whereof we 'ha ve hereunto. 

